Encapsulated quantum sized doped semiconductor particles and method of manufacturing same

• US 6,048,616 A
• Filed: 10/04/1994
• Issued: 04/11/2000
• Est. Priority Date: 04/21/1993
• Status: Expired due to Fees

• Current Assignee: Philips Electronics North America Corporation (Koninklijke Philips N.V.)
• Original Assignee: Philips Electronics North America Corporation (Koninklijke Philips N.V.)
• Inventors: Racz, Jacqueline, Gallagher, Dennis, Bhargava, Rameshwar
• Primary Examiner(s): KRYNSKI, WILLIAM A
• Application Number:
  US08/318,034
• Time in Patent Office: 2,016 Days
• Field of Search: 428/407, 428/403, 428/688, 428/689, 428/690, 428/917, 428/923, 428/570, 428/573, 252/500, 252/501.1, 252/518, 313/502, 313/503
• US Class Current: 428/407
• CPC Class Codes: C09K 11/00 Luminescent, e.g. electroluminescent, chemiluminescent materials
• CPC Class Codes: C09K 11/025 non-luminescent particle coatings or suspension media
• CPC Class Codes: C09K 11/574 with zinc or cadmium
• CPC Class Codes: H05B 33/14 characterised by the chemical or physical composition or the arrangement of the electroluminescent material , or by the simultaneous addition of the electroluminescent material in or onto the light source
• CPC Class Codes: H05B 33/18 characterised by the nature or concentration of the activator
• CPC Class Codes: H05B 33/20 characterised by the chemical or physical composition or the arrangement of the material in which the electroluminescent material is embedded
• CPC Class Codes: Y10S 428/917 Electroluminescent
• CPC Class Codes: Y10T 428/12181 Composite powder [e.g., coated, etc.]
• CPC Class Codes: Y10T 428/12201 Width or thickness variation or marginal cuts repeating longitudinally
• CPC Class Codes: Y10T 428/2991 Coated
• CPC Class Codes: Y10T 428/2998 including synthetic resin or polymer

Abstract

Doped encapsulated semiconductor nanoparticles of a size (<100 Å) which exhibit quantum effects. The nanoparticles are precipitated and coated with a surfactant by precipitation in an organometallic reaction. The luminescence of the particles may be increased by a further UV curing step.

Claims

1. A chemically doped precipitated particle of semiconductor material of less than 100 Å

in diameter encapsulated with a surfactant, the surfactant maintaining a quantum confinement of said particle and further providing a surface passivation of said particle, the dopant concentration of said particle being 0.5-1.0%.

2. The doped particle as claimed in claim 1 wherein said doped particle comprises ZnS doped with Mn.

3. The doped particle as claimed in claim 1 wherein said surfactant comprises poly(methylmethacrylate).

4. The doped particle as claimed in claim 1 wherein said particle has been cured by exposure to UV light.

5. The doped particle as claimed in claim 1 wherein said particle is a phosphor.

6. A particle of semiconductor material of less than 100 Å

in diameter, said particle chemically doped having a dopant of 0.5-1.0% concentration therein and encapsulated with a surfactant, the surfactant maintaining a quantum confinement of said particle and further providing a surface passivation of said particle.

7. The particle of claim 6 in which said dopant is a phosphor activator and said particle is a phosphor host.

8. The particle of claim 6 in which said surfactant is UV cured.

9. The particle of claim 6 in which said surfactant is poly(methylmethacrylate).

10. The particle of claim 6 in which said particle comprises ZnS.

11. The particle of claim 6 in which said dopant is Mn.

12. The particle as claimed in claim 6 wherein the particle is selected from the group consisting of zinc sulfide, zinc selinide, zinc telluride, cadmium sulfide and cadmium selinide.

13. The particle as claimed in claim 6 wherein the dopant is selected from the group consisting of manganese, terbium, copper, silver, thallium, cerium, chromium and titanium.

14. The particle of claim 6 in which said surfactant is methacrylic acid.